Joint for sheet piles



jan. 8, 1952 A, SCHAACK 2,581,717

JOINT FOR SHEET PILES Filed July 30, 1947 Patented Jan. 8, 1952 JOINT FOR SHEET PILES August ASchaack, Esch/Alzette, Luxembourg, assignor to Acieries yReunies de Burbach-Eich- Dudelange Societe Anonyme, Luxembourg,

Grand Duchy of Luxembourg,

Luxembourg a company of Application July 30, 1947, Serial No. 764,748 In Luxembourg December 28, 1943 'section' 1, Public Law 690, August s, 1945 `Patent expires December 28, 1963 This inventionl relates to joints for sheet piles, and more particularly to. joints. of the type in which connection'between successive or adjacent "sheet: piles is effected" by the inter-engagement of joint portions of bifurcated cross-section, the furcations of each joint portion comprising a free end or edge hook and an inwardly spaced claw,l the space between `the hook and claw affording a channel to receive as a snug t a correspondingly shaped hook on the adjacent sheet pile, the'claw and `hook on the latter pile receiving between them the hook of the other pile. This form of joint is referred to as a double hook joint.

As the result of compression and tensile strains the known forms of these double hook joints have a tendency to spread or open out so that the joints loosen. The object of the present invention is to remedy this weakness or to increase the strength of the joints without introducing added bulkiness or protrusion of the joints laterally beyond that which at present obtains.

According to this invention a double hook joint for sheet piles is characterised in that the peak or ridge of the free edge of each hook portion is so related to its inner or root part that when a joint is effected, the shortest distance across the peaks or ridges of the two hook portions is contained in a plane parallel with the planes of the sheet piles.

The invention will now be more clearly understood by reference to the accompanying drawings in which:

Figure 1 shows a known cross-section of joint for sheet piles; and

Figure 2 is a cross-section through a joint forming an embodiment of the present invention.

Referring to the drawings, the webs c and d of the two sheet piles have in common triangular cross-section hooks e at the ends of tenons h formed co-extensive with the webs, the peaks or ridges of the hooks e forming the appropriate free ends or edges of the sheet piles. spaced inwardly from each hook e is a claw y inclined so as to be closely along the inclined side e1 of the appropriate hook e, this side e1 being that which is most remote from the claw g of the sheet carrying such hook. Thus each hook e slides in a corresponding channel constituted by the sides g2, h2 and e2, the sides h2 being at right angles to the base sides e2 parallel with the sides e3 of the hooks e, so that the apices e4 of the hooks e of each joint are staggered. That is, they form the termini of a diagonal S-O-Sl, in which O is at the centre of the bases e2, the sides h2, e2 and e3 2 appropriate toeach hook forming a right angle Z in the form shown in Figure 1. Y i

Also, the base portion e2 of each hook is normal or perpendicular with respect to the plane of the sheet pile, so that during tractive effort the fiat base portions ez'of the hooks abutagainst each other in a plane transverse to the mean direction of tensile strain.v v 4 i It will be noted that the whole of the joint constituted by the inter-engaging hooks is `unilateral relative to the co-planar faces c and d( of the sheet piles, so that on one side ofthe assembly of piles there are no lateral projections, and in the present invention care is taken to keep to this feature.

However, in maintaining the said uni-lateral disposition of each complete joint in the known arrangement shown in Figure 1, the staggering or stepping of the peaks e4- tends to cause the compression load on the sheet piles at the joint to be applied along the diagonal s-o-Sl and to unduly strain and often bend outwards the claws g away from their sheet piles, by reason of the sides e3 tending merely to slide along the sides h2 in the direction parallel with the plane of the webs c and d and thereby transferring the whole of the load across the sides e1 and g2. Also by reason of the sides h2 and e3 being parallel with each other and the planes of the piles, it is not possible to widen the neck parts b` and b' of the tenons h without deforming at least one of the sheet piles adjacent the appropriate neck part b or b', particularly the sheet pile d. But it is found that under tensile strain there is a tendency for the tenons 71, to bend at the parts b and b' thus weakening the joint and also causing the claws y to spread outwards.

By modifying the joint as shown in Figure 2, i. e. by locating each peak or ridge so that 1t is on a line perpendicular to the appropriate base e2 at the centre O, i. e. parallel with the plane of each web ,c and d, the tenon portion h is thicker and therefore stronger at its root b (or b') whilst maintaining the same thickness a and a' at its outer ends as occurs at the like parts in the known joint shown in Figure 1, and without the necessity of increasing the total or effective width of the cross-section of the joint. Also the roots g' of the claws y can be kept to sturdy proportions and the overhang Z from the straight parts of the piles c and d can be kept shorter than the known form of joint shown in Figure l. It will be seen by reference to Figure 2 that the proposed modification of the form of joint in question can be stated as characterised in that the line S-O-S1 is perpendicular to the abutting bases ez or parallel with the planes of the sheet piles, and that this depends to some extent by'thefact that in order to achieve' the foregoing results the hook e is disposed practically wholly unilaterally n of the plane of the web.

The strength of the joint may be brought tous A a sheet pile comprising a main web c or d with complementary hook-joint forming marginal parts at its ends located uni-laterally of one face Y of the web, said marginal parts each comprising a tenon h co-extensive with the web c or d and formed with a substantially triangular outer end hook e, and a claw g spaced inwardly of the hook e and having an inner side g2 forming with the inner side h2 of ther adjacent tenonandthebase side e2 'of the adjacent substantially triangular hook e a channel complementary with one of the said hooks, the two hooks having peaks e4 located in a common plane- S-O-S1 parallel with 'the plane of the web and intersecting.approximately the centres of the base sides e? of the hooks, which base sides are normal to the plane of the web and diagonal with respect to the rinner sides h2 of the said tenons, so that the root ends b and b of the tenons, i. e. those which join the normai web c or d are thicker than the outer ends a and a' which join the said hooks'.

I claim: l

A sheet pile comprising a main web with complementary hook-joint forming marginal parts vat its ends located uni-laterally of one face of theV web, said marginal parts "each comprising a tenon co-extensive with the web and formed with -a substantially triangular outer end hook, and

avclaw` spaced inwardly of the hook and having an inner side forming with the inner side of the adjacent tenon andthe base side of the adjacent substantially triangular hook a channel complementary with one of the said hooks. the two hooks having peaks located in a common plane parallel with the plane of the web and intersecting approximately the centres of the base sides of the hooks, which base sides are normal to the plane of the web and diagonal with respect to the inner sides of the said tenons, so that the root ends of the tenons, i. e. those which join a normal web-,vare thicker than the outer ends which join the said hooks.

i 1 AUGUST SCHAACK.

mari:imNcEsv CITED The following references arel of record in the le of this patent:

UNITED STATES PATENTS Great Britain 1926 

